Conductivity cell



May 22, 1928. l. B. SMITH coNDUcTIvI'fY CELL Filed May 20, 1925 INVENTOR n mu km x mm kv UNI l 7( ATTORNEY.V

Patented May 22, 192s.

UNITED STATES ,iifA'riazia'rA oF-rioni.

IBvING B. SMITH, or A iiinLnn,l PENNSYLVANIA, AssIGNoR'To Lnnns a NoItrHnUr comANY, or' PHILADELPHIA, PENNSYLVANIA, A' CORPORATION or PENNSYL- VARIA.

CONDUGTIVITY CELL.

i Application fiieaviiiayl 20, 1925. seriaimi 31,507.

My invention relates to apparatus for measuring the resistivity or conductivity of materials whoseA resistance change with temperature, as an electrolyte. n

In measuring electrical .conductivity or resistivity ofl electrolytes, 1t 1s customary to immerse two electrodes in the solution .and measure the resistance-between electrodes. Heretofore, theelectrodes Yhave been held in fixed relation one to the'other by insulating material such as glass or porcelain. The use of such materials,'however, is objectionable in various respects, among which may be `mentioned-the fragility of glass or porcelain and its tendency'to crack when sub]ected to ,rapid temperature change. Wires having a small diameter can be `successfully sealed into glass or porcelain 'and used as electrodes but the resulting structure is not of sutiicient strength to prevent bending. 'Furthermorm apparatus of this character is often vprovided with va metallic housing for attachment to a pipe line or vat and when glass or porcelain is used as the insulating merial.

Further, in ,accordance with my invention anyone or more of electrodes or conductive bodies adapted for insertion in an electro- -lyte are initially coated or provided in part at 4least with capsules offametal that will not react with the electrolyte.

For an illustration Qfone- .of the various forms my structure'may take, 'reference is to be hadto the accompanying rdrawing, in

which:

Figure 1 is a. longitudinal sectional view of structure Yembodying my invention.

dium between the electrodes and the hous' i relation withthefmoldable-insulating mate-- Fig. 2 is a. sectional view on'an, enlarged scale of my improved apparatus.v f

Referring to Fig. 1, W indicates .the-'wall ofany vessel, such'as a condensate-chamber 1' or hot well on a steam condenser, or of any`v e other chamber, pipe, etc., the conte'ntswheref ofare either at rest or in motion. 4.

The interior ofthe vessel will be understood as lying to the 'right of the wall W and the exterior 'as lying to the left thereof. Threaded into an aperturein the wall W is a pipe or nipple 1 alsothreaded into the valve structure V, preferably a gate valve comprising the valve seat members 2 and 3,

with which coacts the movable valve mem- 'l bei' or gate 4 actuated by the screw 5 thread- ,ed in the member 6 and in turn actuated byl the hand wheel (not shown) on the stem 4a.

In'the other'end of the body of the'yalve through the wall of which may be threaded a drain cock 9. AThe other end ofthe nipple 8 is threaded into the member. 10- forming with the member 11 a ground union, the members 10 an'd 11 being. held inengage# ment with each other by the nut member 12.

structure is threaded the pipe ornipple 8 j Also threaded into the union member 11 isy the pipe or nipple 13 threaded into the mem-4 ber 14 which, withthe sleeve 15 threaded thereon,.'forms. astuiing box or gland'.

Extending longitudinally through the gland lor -stuing box, nipple 13, ground union, nipple 8,- gate valve, and nipple llis the tube'or pipe 16 of brass, nickel, or other is the packing 'material 17 forced into intimate contactwith the exterior of the tubeI 16 by screwing-wup the nutmember 15.

Secured within the tube 16 as hereinafter described are the electro-conducting members, electrodes, or electrode leads 17,A 18 terminating at onev end in the electrodes proper 19 and 20, theirother ends being connected tofs'uiltable conductors 21 and 22. Threaded to the end of the tube'16 refmote from the electrodes proper are' the collar 23 and couplings O24, a cap 25 v'being threaded on the coupling and adapted to exert sui-table compression upon the soft rubber plug In "assembling improved rdevicejtlie .electrodes .are properly positionedwithin .suitablematerial- In the stung box 14, 15

the tube 16 and the various parts are th`en rigidly held in spaced relation by suitable gripping mechanism. Suitable m'old members are then Yplaced* in position, the .mold- Ving material 27 introduced, and' melding operations, as application of heat and pressure effected. After the material solidiiies,`

the'mold members are removed. An insulating compound 33 of any character which is solid at ordinary temperatures may poured into the tube 16 while hot, thereafter congealing around the electrode leads.-

17 and 18. Preferably, the ,innersurface of the tube 16 may be formed with a groove or rooves 28 with which .the moldable materia inter# locks to effect a rigid union and a joint more resistive to the entry of liquid2 YIf desired,

the structure may be made still .more rigidV and effective against the entry of liquid by' the provision at the end of the tube 16 of an extending collar 29 having a reduced outer Y diameter, against which the moldable Ina-- Vterial impinges with considerable pressure.

Frther, if desired amore intimate relation maybe effected between the electrodeleads 17 and 18 and= the moldable material '27 by the provision rof knurled'surfaces 30 on one or 'both of the electrode leads. e

In--a device constructedl as described the electrode must made relatively large in size and, t ere-fore, it is desirable to use inexpensive' ase. metal, such -as hard copper,

'nickeL-Or steel. Metal of thischaracter is fnotfsuitableffor insertion into some solu.

tions, and to remedy this defect thincoatings or capsules 31 of noble' metal, such as 5 ofV gold'. or .plat'inum, preferably -,pl'atinized,

maybe deposited-on or forced over the ends 40 of the electrodes. The capsules or COB-tings `are. 1'1sual ly.;applied .tothe electrodes prior to the moldingoperaon' Yand preferably theycxtnda suicientdistance along the willc ontact therewith as indicated at '32 thereafter surround the Eig.'2, these metals beingpreferable. When coated in this manne`r,.the moldable material will adhereY mora frmlylw its an additional measure ofv security against` Aleakage of the liquid Eeven under high presing surface thereby giving WhatIclaimisz f' 1 Electrical ap l ofreplating Vture and a' portion of said capsule.

seal the base metal" com-Q duced Vouter diameter, electrode structure within said casing, and means comprising Q5 moldable material forming al` liquid tight joint with said structure and. impingmg againstsaid projection on the exterior thereof to form a liquid tight joint at said casing. T2. Electrical measuring apparatus l comprising .casing `of one/metal coabed with another metal, electrode structure said casing, and means comprising moldable material aroundsaid electrode structure and effecting an intimate contact with ing metal of said casing. Y

3. Electrical measuring ap aratuscom .prising a `casing having a p ated surface, electrode structure within' said casing, and' means comprising moldable material eiectifng an intimate contact withsaid plated surace.

4. Electrical measuring apparatus comf4 prising a brass casing with a gold-plated portion, electrode structure AWitbinsaid casing, and means 'comprising moldable material effecting an intimate contact with saidv gold-plated casing. Y ,fr i

. 5. Electrical measuring `apparatus for Jintroduction into an electroyte electrodestructure of one metal, a ca sule' ofanother metal carried thereby, and msuateial molded around said 4struc- 6. Electrical measuring ,apparatus for vs troduction into .an electrolyte comprising-- electrode structureiof base? metal, acapsule .carried thereby, 'and insulatisn material molded around a portion of sai and capsule. 7.' Electrical measuring structure apparatus forin- I' -trdnction intoganelectrovyte Icomprising electrode structureof base'metal, a capsule of noble metal carried thereby, and insulating material molded around Aa portion of said structure and capsule.

-8.- Electrical measuring apparatus for in troduction into an electroyte comprising f electrode structure of base metal, a go d cap-'-v molded around a vI Joi'tion o f said structure-- andcaps'ule. W Y

9. Electrical measuring a paratus for 'introduction into an electro yte comprising electrode structure of hard copper, a:- capsule carried thereby, and Y molded around a, p01 'tion of said structure and ca sule carried thereby, and insulating material` 11o.

lectrical ini- Y @auction intgn elmlyta comprisingm electrode structureof hard copper, a gold capsule thereby, andiinsulating ma terialmolded aroundapol'tionofsaidstr'uc-` mme-r.. smrn.

the coat- 75 j' .comprising '90 Y 

